Update README with per-module schematic screenshots and BOM

Replace the single full-schematic screenshot with individual per-module
screenshots (audio, MIDI/Arduino, power delivery, USB, top case 3D).
Add a Bill of Materials section auto-generated from the KiCad netlist
using parse_netlist.py (sexpdata), listing 160 components grouped by
schematic sheet with human-readable descriptions.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -106,9 +106,129 @@ kicad-thirdparty-footprints/    Third-party footprints (CM5, DAC, RCA jacks)
 - **JLC2KiCad** — importing JLCPCB component libraries into KiCad
 - **JLCPCB** — PCB fabrication and assembly
 
-## Schematic
+## Schematics
 
-![Full schematic](screenshots/Screenshot%202026-02-08%20at%2019.56.48.png)
+### Audio Outputs
+![Audio outputs schematic — DAC, RCA, and headphone jacks](screenshots/audio_2026-02-17.png)
+
+### MIDI / Arduino Controller
+![MIDI Arduino schematic — ATmega32U4, crystal, and JST connectors](screenshots/midi_arduino_2026-02-17.png)
+
+### Power Delivery
+![Power delivery schematic — USB-C PD, buck converter, LDOs](screenshots/power_delivery_2026-02-17.png)
+
+### USB Ports
+![USB ports schematic — USB-A, USB-C, orientation mux, ESD protection](screenshots/usb_2026-02-17.png)
+
+### Top Case 3D Render
+![Top case 3D render — chassis with jog wheel and button cutouts](screenshots/top_case_3d_2026-02-17.png)
+
+## Bill of Materials by Module
+
+*Auto-generated from the KiCad netlist — 160 components total.*
+
+### Root — Raspberry Pi CM5 compute module, status LEDs, fan connector, RTC battery, and top-level glue logic
+
+| Ref | Value | Description |
+|-----|-------|-------------|
+| BT1 | CR2032-BS-6-1 | CR2032 coin cell holder (RTC backup) |
+| D1 | PSC-1608U52GC-G4 | Green LED 780mcd |
+| D2 | XL-1608UBC-04 | Blue LED |
+| J1 | J_FAN_PWM | 4-pin JST connector for PWM fan |
+| SW1 | DSWB05LHGET | 5-position DIP switch |
+| SW2 | PWR_BUT_CM5 | Push button (CM5 power) |
+| U1 | Compute_Module_5_Functional | Raspberry Pi Compute Module 5 |
+
+Plus 1 capacitors, 10 resistors.
+
+### Arduino MIDI — ATmega32U4 USB MIDI controller, 16 MHz crystal, JST connectors for buttons/encoders/jog wheel
+
+| Ref | Value | Description |
+|-----|-------|-------------|
+| J16 | J_JOG | 4-pin JST — jog wheel quadrature encoder |
+| J17 | J_PLAY | 6-pin JST — Play + Cue buttons and LEDs |
+| J18 | J_ENCODER_BACK | 7-pin JST — browse rotary encoder + Back button + LED |
+| J19 | J_TOUCH | 2-pin JST — jog wheel capacitive touch sensor |
+| J20 | J_LOOP | 8-pin JST — Loop In/Out/Reloop buttons and LEDs |
+| J21 | J_MASTER_TEMPO | 4-pin JST — Master Tempo button + LED |
+| J22 | J_TEMPO | 5-pin JST — tempo fader (analog) + Tempo Reset button + LED |
+| SW4 | RESET_BTN | Push button (ATmega reset) |
+| U14 | ATmega32U4-A | 16 MHz, 32 kB Flash, USB 2.0, TQFP-44 — MIDI controller |
+| X1 | X322516MLB4SI | 16 MHz SMD crystal, 9 pF |
+
+Plus 10 capacitors, 2 resistors.
+
+### Audio Outputs — I2S DAC (PCM5242), RCA stereo pair, 6.35 mm and 3.5 mm headphone jacks, and analog output filtering
+
+| Ref | Value | Description |
+|-----|-------|-------------|
+| FB1 | ~ | 600 Ω @ 100 MHz ferrite bead (power filtering) |
+| J2 | PJ-611E | 6.35 mm (1/4") headphone jack |
+| J3 | J_RCA_L (white) | RCA jack — left channel |
+| J4 | J_RCA_R (red) | RCA jack — right channel |
+| J5 | PJ-320D | 3.5 mm headphone jack |
+| U2 | PCM5122PW | TI PCM5122 — 32-bit 384 kHz stereo DAC, 112 dB DNR |
+
+Plus 12 capacitors, 3 resistors.
+
+### HDMI and Ethernet — Dual micro-HDMI outputs (touchscreen + debug), gigabit Ethernet via RJ45
+
+| Ref | Value | Description |
+|-----|-------|-------------|
+| J12 | HR911130A | RJ45 Ethernet jack with integrated magnetics |
+| J13 | PI HDMI_0 | Micro-HDMI Type D connector (touchscreen) |
+| J14 | PI HDMI_1 | Micro-HDMI Type D connector (debug/secondary) |
+
+Plus 2 resistors.
+
+### Power Delivery — USB-C PD input (CH224K negotiation), 20 V-to-5 V buck (SY8368AQQC), 3.3 V LDO (AP2112K), USB power switches (AP2553W)
+
+| Ref | Value | Description |
+|-----|-------|-------------|
+| D3 | KT-0603R | Red LED (power indicator) |
+| D4 | BZT52C3V3S | 3.3 V Zener diode (voltage clamping) |
+| D5 | PSC-1608U52GC-G4 | Green LED (power-good indicator) |
+| D6 | KT-0603R | Red LED (fault indicator) |
+| J15 | USB_C_Receptacle_USB2.0_16P | USB-C receptacle (power input) |
+| SW3 | SW_MAIN_POWER | Main power toggle switch |
+| U10 | AP2112K-3.3 | 3.3 V LDO — digital power supply (600 mA) |
+| U11 | AP2112K-3.3 | 3.3 V LDO — clean analog supply for PCM5242 |
+| U12 | CH224K | USB PD 3.0/2.0 sink controller (negotiates 20 V) |
+| U13 | SY8368AQQC | Synchronous buck converter (20 V → 5 V) |
+
+Plus 25 capacitors, 9 resistors, 1 inductors.
+
+### Test Points — Debug and measurement test points for key signals
+
+| Ref | Value | Description |
+|-----|-------|-------------|
+| H1–H4 | MountingHole | PCB mounting holes (×4) |
+| J6 | J_ISP_ATMEGA | 6-pin ISP header for ATmega programming |
+| J7 | J_I2C | 4-pin I2C debug header |
+| TP1 | TP_20V_USB_RAIL | 20 V USB power rail |
+| TP2 | TP_20V_USB | 20 V post-switch |
+| TP3 | TP_3.3_DGTL | 3.3 V digital rail |
+| TP4 | TP_5V | 5 V rail |
+| TP5 | TP_3.3_ANALOG | 3.3 V analog rail |
+| TP6 | TP_I2C_SDA | I2C SDA line |
+| TP7 | TP_GND | Ground reference |
+| TP8 | TP_I2C_SCL | I2C SCL line |
+| TP9 | TP_I2S_BCK | I2S bit clock |
+| TP10 | TP_I2S_LRCK | I2S left/right clock |
+| TP11 | TP_I2S_DIN | I2S data in |
+
+### USB DJ Ports — USB-A 3.0 (Rekordbox sticks), USB-A power-only, USB-C 2.0, orientation mux (HD3SS3220), signal switch (HD3SS3212), and ESD protection
+
+| Ref | Value | Description |
+|-----|-------|-------------|
+| J10 | USB_DJ_STICK | USB 3.0 Type-A — Rekordbox USB sticks |
+| J11 | USB_SCREEN | USB 3.0 Type-A — touchscreen USB interface |
+| J8 | AUX POWER USB_A | USB Type-A — auxiliary power output (no data) |
+| J9 | USB_C_Receptacle_USB2.0_16P | USB-C receptacle (general connectivity) |
+| U3–U5, U9 | AP2553W6-7 | USB power switches with current limiting (×4) |
+| U6–U8 | USBLC6-2SC6 | ESD protection diodes, 2 data lines (×3) |
+
+Plus 10 capacitors, 11 resistors.
 
 ## License
 

parse_netlist.py

@@ -0,0 +1,182 @@
+# /// script
+# requires-python = ">=3.10"
+# dependencies = ["sexpdata"]
+# ///
+"""Parse KiCad netlist (.net) and output per-module component summary as Markdown."""
+
+import json
+import sys
+from collections import defaultdict
+from pathlib import Path
+
+import sexpdata
+
+
+def sym_str(val):
+    """Convert sexpdata Symbol or string to plain string."""
+    if isinstance(val, sexpdata.Symbol):
+        return val.value()
+    return str(val)
+
+
+def find_entries(sexpr, key):
+    """Find all sub-lists whose first element matches key."""
+    results = []
+    if isinstance(sexpr, list):
+        if len(sexpr) > 0 and sym_str(sexpr[0]) == key:
+            results.append(sexpr)
+        for item in sexpr:
+            results.extend(find_entries(item, key))
+    return results
+
+
+def find_entry(sexpr, key):
+    """Find first sub-list whose first element matches key."""
+    entries = find_entries(sexpr, key)
+    return entries[0] if entries else None
+
+
+def get_value(sexpr, key):
+    """Get the string value of (key value) from a list."""
+    entry = find_entry(sexpr, key)
+    if entry and len(entry) > 1:
+        return sym_str(entry[1])
+    return ""
+
+
+def get_property(comp, prop_name):
+    """Get a named property value from a component."""
+    for item in comp:
+        if isinstance(item, list) and len(item) >= 3:
+            if sym_str(item[0]) == "property":
+                name_entry = find_entry(item, "name")
+                val_entry = find_entry(item, "value")
+                if name_entry and val_entry:
+                    if sym_str(name_entry[1]) == prop_name:
+                        return sym_str(val_entry[1])
+    return ""
+
+
+def parse_netlist(net_path: Path):
+    with open(net_path) as f:
+        data = sexpdata.loads(f.read())
+
+    # Parse sheet names from the design section
+    design = find_entry(data, "design")
+    sheets = find_entries(design, "sheet")
+    sheet_map = {}  # tstamp path -> sheet name
+    for sheet in sheets:
+        name = get_value(sheet, "name")
+        sheet_map[name] = name
+
+    # Parse components
+    components_section = find_entry(data, "components")
+    comps = find_entries(components_section, "comp")
+
+    modules = defaultdict(list)
+    for comp in comps:
+        ref = get_value(comp, "ref")
+        value = get_value(comp, "value")
+        description = get_value(comp, "description")
+        footprint = get_value(comp, "footprint")
+
+        # Get sheet path name
+        sheetpath = find_entry(comp, "sheetpath")
+        sheet_name = get_value(sheetpath, "names") if sheetpath else "/"
+
+        # Get libsource part name
+        libsource = find_entry(comp, "libsource")
+        part = get_value(libsource, "part") if libsource else ""
+
+        modules[sheet_name].append({
+            "ref": ref,
+            "value": value,
+            "part": part,
+            "description": description,
+            "footprint": footprint,
+        })
+
+    return modules
+
+
+SHEET_DESCRIPTIONS = {
+    "/": "Root — Raspberry Pi CM5 compute module, status LEDs, fan connector, RTC battery, and top-level glue logic",
+    "/Audio Outputs/": "Audio Outputs — I2S DAC (PCM5242), RCA stereo pair, 6.35mm and 3.5mm headphone jacks, and analog output filtering",
+    "/Test Points/": "Test Points — Debug and measurement test points for key signals",
+    "/USB DJ Ports/": "USB DJ Ports — USB-A 3.0 (Rekordbox sticks), USB-A power-only, USB-C 2.0, orientation mux (HD3SS3220), signal switch (HD3SS3212), and ESD protection",
+    "/HDMI and Ethernet/": "HDMI and Ethernet — Dual micro-HDMI outputs (touchscreen + debug), gigabit Ethernet via RJ45",
+    "/Power Delivery/": "Power Delivery — USB-C PD input (CH224K negotiation), 20V-to-5V buck (SY8368AQQC), 3.3V LDO (AP2112K), USB power switches (AP2553W)",
+    "/Arduino MIDI/": "Arduino MIDI — ATmega32U4 USB MIDI controller, 16MHz crystal, JST connectors for buttons/encoders/jog wheel",
+}
+
+
+def format_markdown(modules: dict) -> str:
+    """Format parsed modules as a Markdown section."""
+    lines = []
+    lines.append("## Bill of Materials by Module")
+    lines.append("")
+    lines.append(f"*Auto-generated from the KiCad netlist — {sum(len(v) for v in modules.values())} components total.*")
+    lines.append("")
+
+    # Sort: Root first, then alphabetical
+    def sort_key(name):
+        if name == "/":
+            return (0, "")
+        return (1, name)
+
+    for sheet_name in sorted(modules.keys(), key=sort_key):
+        comps = modules[sheet_name]
+        desc = SHEET_DESCRIPTIONS.get(sheet_name, sheet_name.strip("/"))
+        lines.append(f"### {desc}")
+        lines.append("")
+
+        # Group by reference prefix (letter part) for a summary
+        by_prefix = defaultdict(list)
+        for c in comps:
+            prefix = "".join(ch for ch in c["ref"] if ch.isalpha())
+            by_prefix[prefix].append(c)
+
+        # Filter out purely passive groups from detailed listing
+        # but still show notable ICs/connectors
+        notable = []
+        passives = defaultdict(int)
+
+        for c in sorted(comps, key=lambda x: x["ref"]):
+            prefix = "".join(ch for ch in c["ref"] if ch.isalpha())
+            if prefix in ("R", "C", "L"):
+                passives[prefix] += 1
+            else:
+                notable.append(c)
+
+        passive_summary = []
+        prefix_names = {"R": "resistors", "C": "capacitors", "L": "inductors"}
+        for p in ("C", "R", "L"):
+            if passives[p]:
+                passive_summary.append(f"{passives[p]} {prefix_names[p]}")
+
+        if notable:
+            lines.append("| Ref | Value | Description |")
+            lines.append("|-----|-------|-------------|")
+            for c in notable:
+                desc_text = c["description"] or c["part"]
+                # Truncate very long descriptions
+                if len(desc_text) > 80:
+                    desc_text = desc_text[:77] + "..."
+                lines.append(f"| {c['ref']} | {c['value']} | {desc_text} |")
+            lines.append("")
+
+        if passive_summary:
+            lines.append(f"Plus {', '.join(passive_summary)}.")
+            lines.append("")
+
+    return "\n".join(lines)
+
+
+def main():
+    net_path = Path(sys.argv[1]) if len(sys.argv) > 1 else Path("CDJ-MainBoard_2026-02-17.net")
+    modules = parse_netlist(net_path)
+    print(format_markdown(modules))
+
+
+if __name__ == "__main__":
+    main()